'Nobody Can Prove' Russian Link to Ukraine Rebels, Diplomat Says

The United States has no proof Moscow is amassing heavy weapons along its Ukrainian border and backing separatists believed to have shot down Malaysia Airlines Flight MH17, according to a Russian diplomat. Leonid P. Moiseev, Vladimir Putin's ambassador to Singapore, made the denial hours after Barack Obama imposed harsh new sanctions on Russian banks aimed at forcing the Kremlin to withdraw its support for the rebels.